Corneal epithelium integrity and corneal sensory innervation play a pivotal role in maintaining ocular surface health (Tseng et al., 1997). Clinical conditions leading to corneal nerve disruption associated with epithelial defects and persistent and progressive corneal ulcers include viral infections, autoimmune and endocrine diseases, thermal and chemical burns, multiple ocular surgeries and V pair ganglion or sensory routes affections (Donzis et al., 1987; Gould, 1967; Hyndiuk et al., 1977; and Liesegang, 1985). Current therapeutic strategies adopted for such conditions include medical therapy (e.g., tear substitutes, topical and systemic drugs), surgical approaches based on amniotic membrane transplantation (Chen et al., 2000), and, quite recently, a panacea of novel compounds, especially growth factors able to promote effectively corneal epithelial re-growth. These molecules, mainly neuropeptides, include epidermal growth factor (Kandarakis et al., 1984), aldose reductase inhibitors (Hosolani et al., 1995), insulin-like growth factor type I associated with Substance P, and nerve growth factor (Lambiase et al., 1998). In particular, amniotic membrane tissue has shown powerful and interesting properties in bringing about the anatomical recovery of the anterior ocular surface from a disease condition, along with observations regarding its composition that include even more growth factors than the list mentioned above (Uchida et al., 2000). Unfortunately, an improvement in the patient's visual outcome following application of amniotic membrane tissue is often unsuccessful (Solomon et al., 2002). Application of the amniotic membrane as a multilayer structure instead of as a monolayer has been somewhat more effective, which may be due to the quantity of amniotic membrane applied biological factors (Prabhasawat, 2001). Cryopreserved human amniotic membrane has been applied to the affected eye of a patient as a patch after defrosting (Kim et al., 1995). The applied patch released a restricted amount of factors to the damaged tissue, but the survival of the human amniotic membrane cells decreased to zero in a few days.
Despite the partial effectiveness of these approaches, these treatments are usually unable to completely restore the affected part, functionally and anatomically. Accordingly, a more effective and efficient approach in treating the symptoms and clinical conditions of ocular diseases and related conditions would be useful.